package com.itheima.zixi3.ZuoYe4;

import java.util.Random;
import java.util.Set;
import java.util.TreeSet;

public class test {
    public static void main(String[] args) {
        Random r=new Random();
        Set<Integer> set=new TreeSet<>();
        while (set.size()<8) {
            int num = r.nextInt(10,20);
            set.add(num);
        }
        System.out.println(set);
    }
}
